First in-beam observation of97Ag ? The three-proton-hole spectrum in100Sn

Abstract

Excited states in 97Ag have been identified for the first time following the reactions 46Ti(SSNi, ep2n) and 64Zn(36Ar, p2n). The population cross sections were 1.0(5)mb and 0.7(3) rob, respectively. The y-decay of the seniority v = 3 states below the I~= (17/2-) and (21/2 +) isomers was investigated. In a search for short lived isomers half lives of t1/2=5(2 ) ns and 2.5(5)ns were found in the N=50 isotones 97Ag, U=(17/2-) and/or (21/2 +) and 95Rh, U=(21/2+). A new isomer was identified in 9Vpd, U=17/2 + with tl/2 = 2.3 (5) ns. The implication of the three-proton hole spectrum in ~~176 for the empirical residual interaction and shell model predictions is discussed.

Nuclear structure study of the neutron deficient cadmium isotopes100, 101, 102Cd

“…For a d5/2 neutron this is observed in the N=51 isomers [1,8] for the corresponding I ~= 17/2 + states. Due to the particlehole character of the n v interaction the stretched coupled states [nggl 2 8+@vd512121/2 + or [nggl~ 8+@VgT/2]Z3/2 + are unfavoured to be isomeric as they decay by an M 1 cascade to the energetically favoured U= 17/2 + or 19/2 + states, respectively.…”

“…Based on previous shell-model approaches for N=50, 51 nuclei [1][2][3]8] and a set of two-body matrix elements derived from the Sussex and Yale codes [35], we have performed a shell-model calculation in the ng9/2, v(ds/2, gv/2, s1/2, d3/2) configuration space. The ~zrc interaction was taken from a calculation of N = 50 nuclei in a rc(pu2, g9/2) configuration space with a seniority conserving interaction E2, 6].…”

“…The neutron magic N=50 nuclei have been studied experimentally up to 9rAg [1] and several shell model studies [2,3] have * CERN-ISOLDE, CH-1211 Genf, Switzerland ** LLNL, Livermore, CA 94550, USA; *** Academia Sinica, LanzhoU, P.R. of China resulted in a good understanding of the proton-proton (rc~c) residual interaction, yielding good agreement with experimental level schemes, binding energies and B(E2) values.…”

Sn100core excitations inAg97

“…However, it remains elusive, and we have to infer its structure by studying excited states of neighboring nuclei. Nuclei closest to 100 Sn with experimentally determined excited states are currently the T z = 1 nuclei 102 Sn [1] and 98 Cd [2] and the T z = 3/2 nuclei 103 Sn [3], 101 In, 99 Cd [4], and 97 Ag [5]. We report here the first spectroscopic information on 100 Sn core excited states in 97 Ag including a core excited isomeric level.…”

In-beam spectroscopy of104Sn

“…The spectroscopic approach to the extremely neutron deficient doubly magic 94 has made substantial progress recently. 97Ag [1] and lo0Cd [2] have been studied in-beam and 98Ag in the 13+/EC decay of 98Cd [3] . From these studies fairly good knowledge of the proton-proton.…”